yes it is, it's a cosworth sized compressor wheel and housing etc.
basically it's a T3 with a compressor wheel of exducer 60mm and trim of 60, that's what was used on a 4wd cosworth and all the t3 turbines were the same.
a stage3 t3 is basically a 4wd cossie turbo, but has a 360 degree bearing to spread the load of thrusting better.